Search-based marketing has come a long way but more advances are anticipated, such as searches that move beyond keywords along with capabilities in image searches and mobile phone-based searches, a Google official stressed Wednesday.

"We have a huge opportunity in front of us to revolutionize the industry of search marketing," said Nicholas Fox, business product management director for Google AdWords, at the Search Engine Strategies conference in San Jose, Calif. AdWords is the search giant's advertising service.

Google, for its part has expanded services to include such capabilities as more advanced queries and a bid simulator for advertising purposes, Fox noted. But keyword advertising remains a bit of a game, with advertisers trying to figure out user searching habits, he said.

"We need to get better at connecting users with advertisers," said Fox. Keywords work well, but there is room for improvement, he said. Google, for its part, offers a search-based keyword crawl, which suggests keywords to advertisers.

Approaches not involving keywords are being pondered, Fox said. In place of keywords, a plumber, for example, might provide details on location of operations and services while a retailer might offer up a list of products or a catalog. "I see the keyword as an intermediary that we came up with five or 10 years ago," to help advertisers target specific queries, Fox said.

Other areas of development include searches based on image recognition. "I think it's an area where we will continue to invest," said Fox. Mobile-based searching, meanwhile, has advanced as sophisticated browsers emerge on phones such as Apple iPhone, Google Android and Palm Pre, he said.

"In many ways, we had a constraint in the past," in getting an ad to fit into a small form factor, but that is changing, Fox said. Mobile phones also offer opportunities in that they present location information as well as more details on what a user is trying to do, he said. Other capabilities starting to happen for phones include voice- and picture-based searches.